Optimize: Allow rules to break error-loop (x2 faster)

jsonschema/_validators.py

@@ -1,7 +1,7 @@
 import re
 
 from jsonschema import _utils
-from jsonschema.exceptions import FormatError, ValidationError
+from jsonschema.exceptions import FormatError, ValidationError, _BreakLoopException
 from jsonschema.compat import iteritems
 
 
@@ -196,6 +196,7 @@ def ref(validator, ref, instance, schema):
     with validator.resolver.resolving(ref) as resolved:
         for error in validator.descend(instance, resolved):
             yield error
+    raise _BreakLoopException()
 
 
 def type_draft3(validator, types, instance, schema):

jsonschema/compat.py

@@ -1,6 +1,9 @@
 from __future__ import unicode_literals
-import sys
+
+from collections import namedtuple
 import operator
+import sys
+
 
 try:
     from collections import MutableMapping, Sequence  # noqa
@@ -13,7 +16,7 @@
     zip = zip
     from io import StringIO
     from urllib.parse import (
-        unquote, urljoin, urlunsplit, SplitResult, urlsplit as _urlsplit
+        unquote, urljoin, urlunsplit, SplitResult, urlsplit as _urlsplit,
     )
     from urllib.request import urlopen
     str_types = str,
@@ -23,7 +26,7 @@
     from itertools import izip as zip  # noqa
     from StringIO import StringIO
     from urlparse import (
-        urljoin, urlunsplit, SplitResult, urlsplit as _urlsplit # noqa
+        urljoin, urlunsplit, SplitResult, urlsplit as _urlsplit, # noqa
     )
     from urllib import unquote  # noqa
     from urllib2 import urlopen  # noqa
@@ -40,14 +43,15 @@ def urlsplit(url):
     return SplitResult(scheme, netloc, path, query, fragment)
 
 
+DefragResult = namedtuple('DefragResult', 'url fragment')
 def urldefrag(url):
     if "#" in url:
         s, n, p, q, frag = urlsplit(url)
         defrag = urlunsplit((s, n, p, q, ''))
     else:
         defrag = url
         frag = ''
-    return defrag, frag
+    return DefragResult(defrag, frag)
 
 
 # flake8: noqa

jsonschema/exceptions.py

@@ -165,6 +165,8 @@ def __unicode__(self):
     if PY3:
         __str__ = __unicode__
 
+class _BreakLoopException(Exception):
+        pass
 
 class ErrorTree(object):
     """